1. Chapter 7 – Periodic Properties of Elements

2. Periodic Trends

3. 1. Atomic Radius: How we measure the size of an atom
The transition metals throw off the trend, so we just remove them

4. Atomic Radius AR

5. Which has the largest atomic radius?
1. K Ca Sc Ti
2. Mg Ca Sr Ba
3. Bi N P As

6. Atomic Radii of Ions
Positive ions have smaller sizes than the neutral atom and negative ions have larger sizes
Determined by interatomic distances in ionic compounds
Ionic size depends on
the nuclear charge.
the number of electrons.
the orbitals in which electrons reside.

7. 2. Ionization Energy: The energy required to remove a valence electron from an atom
The transition metals throw off the trend, so we just remove them

8. 2. Ionization Energy IE

9. Which has higher ionization energy?
Mn Br Ga K

10. 3. Electronegativity: The ability of an atom to attract or pull an electron from another atom when bonded
Noble gases do not have electronegativity!
What do you notice here?

11. 3. Electronegativity EN

12. 4. Reactivity: How likely an atom will react with other atoms
Metals
Nonmetals
Increases as you move down and to the left
Increases as you move up and to the right

13. 4. Reactivity: How likely an atom will react with other atoms

14. Summary of Trends Ionization Energy Electronegativity Atomic Radius
Reactivity

15. 3. Which element is the most electronegative?
Practice
1. Which element has the highest ionization energy?
2. Which element has the largest atomic radius? Na Mg K Ca Na Mg K Ca
3. Which element is the most electronegative? Ge Br Se As